Variables

T-SQL is not only a query language. It also has features common in procedural programming languages. One of the most powerful capabilities of T-SQL is the ability for us to create and use variables.

Variable declaration

A variable represents a named object that holds some value. Variables are defined using the DECLARE statement, followed by the name and type of the variable. A variable’s name must begin with the @ symbol:

DECLARE @VariableName VariableType

It is also common among developers to use the AS keyword when indicating the variable’s type. However, there is no functional difference:

DECLARE @VariableName AS VariableType

Let’s create a variable called ...